1. I'm not sure if you noticed but haejin is getting downvoted too. 
2. Vote selling/vote-buying and self-voting are ultimately about the same in terms of the damage they do to the ability of the system to reward real contributions. Yeah self-voting on spam-ish content might be a bit more bad, but they are both bad. Sorry, but I'm not going to let the fact that there might be some worse case of abuse happening somewhere on the platform that I didn't happen to see prevent me from downvoting the abuse that I do see.